Remote control receiver

ABSTRACT

Receiving relay of the type used in centralised remote control systems in which a single emitter, without any pilot wires, sends telegrams of orders over the electrical energy mains distribution network. These telegrams of orders are received in synchronisation by one or several receiving relays having a vibrating reed and connected in parallel on the mains network. The pulses are formed by modulating a carrier and are superimposed on the mains. The relays are able to decode optionally at least two sorts of telegrams distinguished by a starting pulse which may be short or long. The receiving relay comprises a vibrating reed frequency selector for detecting the first pulse of the telegram of orders to as to actuate a trip lever closing an energisation circuit passing through a starting cam for controlling contacts for supplying a motor with power.

finite States Patent Blouin 51 Aug. 7, 1973 i 1 REMOTE CONTROL RECEIVER Primary Examiner-Ralph D. Blakeslee [75] Inventor: Louis Blouin, Malakoff, France Att?meywln'am Sherman Jerry Presson e a 173] Assignee: Compteurs Schlumberger, [57] ABSTRACT Montrouge, France Receiving relay of the type used in centralised remote Flled? 1972 control systems in which a single emitter, without any Appl. No: 237,009

Foreign Application Priority Data Masson 178/88 pilot wires, sends telegrams of orders over the electrical energy mains distribution network. These telegrams of orders are received in synchronisation by one or several receiving relays having a vibrating reed and connected in parallel on the mains network. The pulses are formed by modulating a carrier and are superimposed on the mains.The relays are able to decode optionally at least two sorts of telegrams distinguished by a starting pulse which may be short or long. The receiving relay comprises a vibrating reed frequency selector for detecting the first pulse of the telegram of orders to as to actuate a trip lever closing an energisation circuitpassing through a starting cam for controlling contacts for supplying a motor with power.

8 Claims, 10 Drawing Figures PATENTEB ms 7 i975 w (9a) I REMOTE CONTROL RECEIVER This motor drives a primary decoding cam which is cut out in the image of the telegram and at least two secondary decoding cams coupled to each other. The primary cam rotates in synchronisation with the transmission of the telegram; the secondary cams rotate at a speed which is a multiple of the speed of the primary cam. Two recesses formed on each secondary cam are spaced apart by an angle proportional to the time separating two order pulses after the interval of time reserved for the first pulse. First and second feeler levers controlled by the recesses execute via the intermediary of bossed cams close and open" orders corresponding respectively to odd and even pulses decoded by the frequency selector. A common catch locks said feeler levers in the absence of pulses. An odd or even order pulse removes the catch and actuates at least one of the feeler levers via the intermediary of the recess presenting itself in synchronisation with said order pulse, such that the bossed cam closes electrical contacts during an odd pulse and opens said contacts for an even pulse.

The Pulsadis centralised remote control system is known in which a single emitter, without any pilot wires, sends telegrams of orders over the electrical energy mains distribution network; these telegrams of orders are received synchronously by one or several receiving relays connected in parallel on the mains network. The pulses are formed by modulating a carrier and are superimposed on the mains. The carrier frequency used may be, for example, 175 Hz for a 50 Hz mains frequency. A telegram of orders is formed by a cycle of pulses whose total duration is 102.25 seconds.

The first interval separating two pulses is fixed at 3.75 seconds and the other intervals are fixed at 2.5 seconds. The order pulses have a duration of 1 second.

In order to execute an order, each receiving relay responds to a code contained in the telegram. There are receiving relays which are sensitive to a telegram A comprising a long starting pulse of 2.5 seconds located at the beginning of the first interval of 3.75 seconds, an order pulse being sent at the beginning of one of the n following intervals.

Other relays are decoded by a telegram B comprising a short starting pulse of 1 second, an order pulse being sent in the same manner as in the case of the telegram A. There are also receiving relays which are decoded by a telegram C comprising a short starting pulse of 1 second, followed by a preselection pulse (1 second) preceding an order pulse of rank n.

A receiving relay which normally responds to code B is also sensitive to code A. With conventional receiving relays, it is not possible to perform a selective decoding and without particular precautions these relays are not compatable within the same remote control network.

The object of the present invention is to remedy these disadvantages and to provide, to this end, remote control receiving relays of identical construction capable of decoding one telegram from two by differentiating them both by the duration of the control pulse and by the rank of the order pulse.

The receiving relay according to the invention, of the type used in centralised remote control systems, comprises:

a vibrating reed frequency selector for detecting the first pulse of a telegram of orders so as to actuate a trip lever for closing an energisation circuit passing through contacts controlled by a starting cam for supplying power to a motor driving a primary decoding cam having a portion cut out in the image of the telegram and at least two secondary decoding cams coupled together, the primary cam turning in synchronisation with the transmission of the telegram, the secondary cams turning at a speed which is a multiple of the speed of the primary cam; two recesses formed on each secondary cam being offset by an angle proportional to the time separating two order pulses after the interval of time reserved for the first pulse; first and second feeler levers controlled by the recesses for executing, via the intermediary of bossed cams, close and open orders corresponding respectively to the odd and even pulses decoded by the frequency selector, a common catch for locking said feeler levers in the absence of pulses; an odd or even order pulse removing the catch and actuating at least one of the feeler levers via the intermediary of the recess presenting itself in synchronisation with said order pulse, such that the bossed cam closes electrical contacts during an odd pulse and opens said contacts for an even pulse.

According to a preferred feature of the invention the cut out portion of the primary cam has a first row of breakable crenelles for forming recesses corresponding to the starting and order pulses of the telegram to be decoded, a first peg rigid with the trip lever engages in a starting recess and at the interior of the hollow profile of said cam during the first pulse, said peg disengages itself when an order recess presents itself such that between said recesses the trip levermaintains closed the motor energisation circuit passing through the contacts of the starting cam.

According to another preferred feature of the invention, the trip lever is equipped with an optional supplementary peg blocked by the rotation'of a hollow profile of the contact controlling cam when the first pulse is short, such that said lever mechanically blocks the frequency selector which becomes insensitive to order pulses transmitted after a first short pulse and for the entire duration of the telegram.

According to another subsidiary feature of the invention, the cut out portion of the primary cam has a second row of breakable crenelles for forming recesses corresponding to the starting and order pulses of the telgram to be decoded, the electrical contacts being opened at the passage of the recesses for unshortcircuiting the winding of the frequency selector and these same contacts being closed outside the recesses for short-circuiting said winding.

According to another subsidiary feature of the invention, a feeler lever executes an order by two successive movements, the first is a rocking of the end of the lever into the recess of the secondary rotating cam, the rocking having the effect of putting into engagement axial teeth provided on the adjacent lateral faces of the feeler lever and of the bossed cam, the second movement is a reverse rocking consecutive to the return of said end onto the exterior profile of the secondary rotating cam, the reverse rocking having the effect of making said teeth advance such that the bossed cam rotates through an angle corresponding to the closing or the opening of the associated electrical contacts.

According to another subsidiary feature of the invention, the bossed cam comprises two sets of axial ratchet teeth disposed symmetrically on its two faces, the feeler levers have a set of axial ratchet teeth bearing elastically against the corresponding teeth of the bossed cam, the teeth of a feeler lever are shifted through half of said proportional angle with respect to the: teeth of the other feeler lever, such that the teeth of a feeler lever which has executed an opening order are in direct engagement at the end of the rotation with the corresponding teeth of the bossed cam whereas the teeth of the other feeler lever are shifted by half a tooth forward with respect to the other teeth of the bossed cam while waiting for the execution of a closing order, such that furthermore said teeth in engagement at the end of the rotation cannot repeat a previously executed order.

According to another subsidiary feature of the invention, the secondary cams are coupled with their respective recesses in phase two by two such that one revolution of each secondary cam executes one order chosen among two possible successive orders.

According to another subsidiary feature of the invention, the secondary cams are coupled with an offset between their respective recesses such that one revolution of each secondary cam executes one order chosen among four possible successive orders.

The invention will be better understood with the aid of the following description and of the accompanying drawings which are given merely by way of example without any limiting character.

FIG. 1 shows an electrical schematic diagram of the principle of the receiving relay forming the subject of the invention;

FIG. 2 is an exploded view in perspective of an embodiment of 'themechanism of the receiving relay according to FIG. 1;

FIG. 3 is a detail of construction of FIG. 2;

FIGS. 4 to 9 are other details of FIG. 2;

FIG. 10 illustrates a diagram of the mode of operation of the receiving relay according to the invention.

In FIG. 1, the receiving relay is connected in parallel on the mains network by terminals 1 and 2. The terminal 2 is connected to the common point d and to a terminal 14a of the winding 14. The terminal 1 is connected to the common point e and to a capacitor 13 connected in series at the point 14b with the winding 14 which can be shunted by contacts 15a and 156. The capacitor 13 and the winding 14 constitute a tuned circuit tuned to the frequency of the carrier forming the pulses; this circuit 13, 14 is thus used in a known manner for obtaining a frequency selection electrically. A motor 10 connected to the common point c is also connected to the common point d through parallel contacts 11a, 11b and 12a, 12b. The contacts 8a, 8b and 9a, 9b connected respectively to the terminals 3, 5 and 6, 7 are operated by the relay in response to the orders that it receives; the manner of this operation will be explained in the course of the present description.

In FIG. 2, a mechanical frequency selector 16 of a known type comprises a magnetic circuit 17, a vibrating reed 18 held at one end by an embedding 19 and provided with a pawl 20 at its other end. A lateral extension 21 of the reed 18 is disposed in the air gap of the magnetic circuit 17. The pawl 20 engages with the periphery of a ratchet wheel or friction wheel 22 mounted on a shaft 23 which drives successively an Oldam coupling 25, a gear train 26 and a cam 27. The assembly of rotating pieces 22'to 27 is returned to a rest position by a spring 29 attached to the point 28 of the cam 27 on the one hand and to a fixed point 24 on the other hand.

In the position shown by FIG. 2, the rest stop 27a of the cam 27 maintains the crank 32 of the disc 33 in a position which corresponds to the rest position of the trip lever 34. The disc 33 is rigid with a shaft 30 securely fastened to a catch 57. For clarity in the drawing, the catch 57 is represented by four pieces 57, S7, 57" and 57" which, in practice, form just a single piece of sufficient width to cover the lugs 51a, 52a and 53a, 54a.

The motor 10 drives, through a reducing gear, on the one hand a shaft 36 rigid with a primary decoding cam 60 and with a primary cycle cam 39, and on the other hand a shaft 37 rigid with a starting cam 38 and with secondary decoding cams 40 and 45 respectively. The shaft 36 and consequently the earns 39, 60 make one revolution per cycle of a duration fixed at 102.5 seconds. .The shaft 37 and consequently the cams 38, 40 and 45 make nine revolutions per cycle (1 to 9, FIG. 10b), namely one revolution in 12.5 seconds. The gear ratios and the times are given merely by way of example.

The contacts 11a, 11b are placed under the dependency of the cam 38 and of the boss 35 of the lever 34 and control the energisation circuit of the motor 10 (see FIG. 1). The contacts 11a and 11b close when the blade of the contact 11a disengages from the recess 38a in order to maintain the energisation circuit of the motor 10 for one revolution (12.5 seconds) of the cam 38 after the motor has started. The contacts 12a, 12b are closed as soon as the blade 121a disengages from the recess 39a in order to maintain the energisation circuit of the motor 10 for one revolution (102.5 seconds) of the cam 39.

The cam 60 with its crenelles (i.e. the upstanding portions between the recesses) performs mechanical and electrical blocking functions. Its periphery comprises two similartracks each presenting a fixed recess 60a and 60b respectively, 18 crenelles such as 61a and 61b, plus a compensation crenelle such as 61a and 61b.

By comparison with the telegram of FIG. 10a; the times represented by the cut-out portions of the primary cam 60 are the following: 3.75 seconds for a fixed recess 60a or 60b; 2.5 seconds for a decoding recess 61 (equivalent to acrenelle 61a or 61b); 8.75 seconds for a compensation crenelle 61a or 61b, with a total of 102.5 seconds for a complete revolution of the cam 60.

The mechanical authorisation for actuating the trip lever 34 is subordinated first to the passage of its pin 62 into the fixed recess such as 600, and then to the passage of this pin 62 into a coding recess such as 61 obtained by breaking off a crenelle 610. FIG. 3 shows a supplementary, optional locking arrangement for the lever 34 which can be used for rendering the receiving relay according to the invention insensitive to starting orders of short duration ('1 second). In this case, a peg 63 placed on the lever 34 engages inside a cup-shaped cam 38b rigid with the cam 38. The lifting of the lever 34 is only possible by the simultaneous release of the peg 63 passing outwardly into the opening 38c and of the peg 62 engaging inwardly into the fixed recess 60a.

The electrical authorisation for actuating the receiving relay is obtained by the opening of the contacts 15a, 15b which short circuit the winding 14 (FIG. 1). The opening of these contacts is obtained by the engagement of the blade 151a into a coding recess similar to 61 obtained by prior rupturing of a crenelle 61b.

The secondary decoding cam 40 comprises two tracks, one of which, 40a, has a recess 42, and the other of which, 40b, has a recess 44. The secondary decoding cam 45, coupled to the cam 40, also comprises two tracks, one of which, 450, has a recess 46, and the other of which, 45b, has a recess 48. It should be recalled that in this embodiment, the cam 40 makes one revolution in 12.5 seconds, so that taking into account the spacing of the pulses of the telegram, the recess 42 is located at lO8 from the position of the origin 0 of the cam 40 (FIGS. 4 and b). This arrangement respects the time of 3.75 seconds corresponding to the first pulse, namely the starting pulse, taken together with the interval that separates it from the first order pulse. The possible positions of the recess 42 are located at 72 from each other after the angle of 108 from the origin position 0 of the cam 40, in order to respect the time of 2.5 seconds which elapses between two order pulses (FIGS. 4 and 10).

The recesses 42, 46 can be put in. phase (FIG. 4) by aligning the earns 40 and 45 identically with each other on the shaft 37. For this purpose, a stud 41 of the cam 45 engages in a hole 49 of the cam 40. A phase shift between the recesses is obtained by shifting the stud 41 into the hole 50, that is to say l44 in the present exampie.

The tracks 40a,'40b and 45a, 45b are followed by corresponding levers S1, 52 and 53, 54 articulated on a shaft 55 and returned individually by springs 56a, 56b, 56c and 56d. These levers each comprise a lug, 51a, 52a and 53a, 54a respectively, which can be retained by the'common catch 57 rigid with the shaft 30.

The internal faces of the levers 51 to 54 have ratchet teeth such as 51b, 52b (visible in the developments of FIGS. 6 to 9) oriented in the direction of the shaft 55. The bossed cam 58 turning on the shaft 55 is disposed between the internal faces of the levers 51, 52. Another bossed cam 55 is disposed in the same manner between the levers 53, 54, the bossed earns 58 and 59 comprising on their two faces ratchet teeth such as 58a, 58b equal in number to the teeth of the levers.

In order to obtain relative motion, which will be explained in the course of the present description, it should be noted that the axial teeth 51b and 52b, corresponding respectively to the levers 51 and 52, are shifted with respect to each other by 36 when these levers are at rest whereas the teeth 58a and 58b of the bossed cam 58 are symmetrical (FIG. 6).

The arrangement of the teeth could be reversed without changing the scope of the invention. The same types of teeth are adopted for the levers 53, and 54, as well as for the bossed cam 59 actuating the contacts 9a, 9b.

The freely turning stack constituted by the levers 51 to 54 and the cams 58, 59 have some axial play obtained by a spring 43 mounted on the shaft 55 between the levers 52, 53 such that the teeth 58a, 58b and the similar teeth of the cam 59 can engage or disengage freely with the corresponding teeth such as 51b, 52b. The stack is retained by a pin'56 fixed on the shaft 55. The contacts 8a, 8b, and 9a, 9b of FIG. 1 are visible in FIG. 2, facing the bossed earns 58, 59. The blade of the movable contact 8a is actuated by the bosses such as 58d (cam 58) and the blade of the movable contact 9a is actuated by the bosses such as 59d (cam 59).

The operation of the receiving relay'is the following. When a telegram is sent along the mains network (FIG.

10), the carrier frequency of its first pulse 0 is applied to the winding 14 as shown in the diagram of FIG. 1. The reed 18, urged by the attraction'of its extension 21, begins to resonate and makes the wheel 22 turn via the intermediary of the pawl 20. The motion is transmitted to the shaft 23, the Oldam coupling 25, the gear train 26 and the cam 27, which stretches the spring 29 by the movable point of attachment 28. The position of the working abutment 27b on the cam 27 is arranged to decode the telegrams first pulse O, which may be short or long. As soon as the abutment 27b encounters the crank 32, and before the duration of the first pulse has elapsed, the disc 33 rotates with its shaft 30. At the end of the first pulse, the crank 32 has rotated sufficiently to lift the trip lever 34, whose pin 62 passes into the recess 60a. The boss 35, in its displacement with the lever 34, releases the blade 11112 which closes the contacts 1 2a, 11b thereby making the starting circuit of the motor 10 (FIGS. 1 and 2). The motor 10 starts and drives the earns 38, and via the intermediary of the shaft 37 on the one hand, and the cams 39, 40 via the shaft 36 on the other hand. The cam 38 displaces the closed contacts 11a and 11b (by means of the blade 111a) so as to replace the blade lllb under the dependancy of the boss 35 and thereby to prepare for the next start. The cam 39 closes the contacts 12a, 12b so as to authorise the permanent operation of the motor 10 during a complete revolution (102.5 seconds) of the cam 60. Simultaneously, the shaft 30 trips the catch 57 in order to release the feeler levers S1 to 54, which remain in their initial position due to the fact that they bear against the non-recessed parts of the tracks 40a, 40b and 45a, 45b.

After a maximum time of 2.5 seconds, when the first starting pulse ceases, the lever 34 falls back and with it the catch 57. At 3.75 seconds, the blade Illa falls back into the recess 38a and opens the motor starting circuit that passes through the contacts Ila, 11b. The motor 10 remains supplied with power by the permanent circuit passing through the contacts 12a, 12b controlled by the cam 39. The winding 14 is short circuited by the contacts 15a, 15b closed by the displacement of the blade 151a coming out of the recess b. Simultaneously, the pin 62 comes out of the recess 60a and passes to the exterior of the cam 60. The relay according to the invention is ready to receive order pulses.

In order to meet the operating needs of certain networks that require at least two types of receiving relays to co-exist, for example, one for long starting pulses and the other for short starting pulses followed by a preselection pulse, it becomes imperative to discriminate the length of the starting pulse. Thus, a receiving relay arranged to operate with a long pulse must remain insensitive to a short starting pulse and for this purpose it will be equipped with a supplementary peg 63 (FIG. 3). In this case, the operation is the following: when a short starting pulse (1 second) is received by the frequency selector 16, the trip lever 34 is lifted as has been described above. At the end of this pulse, the pin 62 falls back out of the recess 60a whereas the pin 63 falls back into the recess 38c and engages at the interior of the cup-shaped cam 38b, so that the lever 34 is blocked in its low position by the pin 63 during a complete revolution of the cam 38b whose rotation is linked with that of the cam 38. When the order pulses are received by the frequency selector 16, even if there were some decoding coincidences with the recesses 60b of the cam 60 which would eliminate the short circuit of the winding 14 by opening the contacts 15a and 15b, the lever 34 will not be lifted by the crank 32, which will be blocked reciprocally by the lever 34. The receiving relay according to the invention will thus be insensitive to order pulses which follow.

By contrast, if thereceiving relay receives a long starting pulse, the'lever 34 maintains the pin 63 for 2.5 seconds, which is a sufficient time to make it'clear the recess 38c and to maintain it at the exterior of the cupshaped cam 38b. Thus the lever 34 is placed in its high position for the entire duration of the rotation of the cam 60. The result is that all the order pulses which follow will be received in synchronisation with the opening of the contacts 15a, 15b and will act on the crank 32 as well as on the catch 57. The receiving relay will thus be sensitive to the order pulses which follow the long starting pulse.

According to the operating conditions of the receiving relays co-existing on a network, the decoding of the order pulses must be able to be performed with different mechanical couplings between the earns 40 and 45 so as to permit, according to the case, the execution of 8 or 16 pairs of orders. These couplings are obtained as has been explained above by the engagement of the stud 41 into the hole 49 if the cams 40, 45 are to be in phase and in the hole 50 if they are to be out of phase.

Whatever be the coupling imposed, the decoding of a pair of order pulses of the telegram by the cams 40 and 45 takes place in the following manner: when a close order pulse is sent in synchronisation, on the one hand, with the decoding conditions imposed by the cam 60 and, on the other hand, with the passage of one of the recesses such as 42, 44, 46, or 48, the crank 32 trips the catch 57 which releases the lug of the corresponding lever, for example 51a for the lever 51. The end 'of the lever 51 engages in the recess 42 under the action of the return spring 56a. The teeth 51b of the lever 51 (see FIGS. 2, 6 and 7) slide (towards the left in FIG. 6) along the corresponding teeth 58a of the bossed cam 58 due to'the axial play permitted by the spring 43, from the position of FIG. 6 to that of FIG. 7. The teeth 51b thus shift through 36 and come into engagement with the teeth 58a (FIG. 7).

At the end of the close order pulse, the end of the lever 51 is lifted back onto the track 400 and the teeth 51b, which are in engagement with the teeth 58a move towards the right in FIG. 7 to make the bossed cam 58 pivot and to bring it into the position of FIG. 8 which corresponds to the closing of the contacts 8a, 8b.

When an open order pulse is sent in the conditions of synchronisation and of decoding indicated above, the crank 32 trips the catch 57 which releases the lug of the corresponding lever, for example 52a for the lever 52. The end of the lever 52 engages in the recess 44 under the action of the return spring 56b. The teeth 52b of the lever 52 (see FIGS. 2 and 8) slide towards the left in FIG. 8 along the corresponding teeth 58b of the bossed cam 58, due to the axial play permitted by the spring 43. The teeth 52b thus shift through 36 and come into engagement with the teeth'58b. At the end of an open" order pulse the end of the lever 52 is lifted back onto the track 40b and the teeth 52b in engagement with the teeth 58b, more toward the right to make the bossed cam 58 pivot and to bring it back into the position of FIG. 6 which corresponds to the opening of the contacts 8a, 8b (or 9a, 9b for the other cam 45).

In the case of a confirmation ofa close order when the contacts 8a and 8b (or and 9b) are already closed (FIG. 8) the teeth 51b recoil by 35 (FIG. 9) without being able to come back into engagement with the teeth 58:: of the bossed cam 58. The contacts 8a, 8b or 9a, 9b remain closed. Similarly, in the case of a confirmation of an open" order when the contacts are already open (FIG. 6), the teeth 52b recoil by 35 without being able to come back into engagement with the teeth 58b (not shown).

I claim:

1. A receiving relay of the type used in centralised remote control systems for receiving in synchronisation a telegram of orders sent by a single emitter, without any pilot wires, over an electrical energy mains distribution network, the telegram being formed by pulses produced by modulating a carrier and superimposed on the mains network, said receiving relay comprising:

a vibrating reed frequency selector tuned to the frequency of the carrier for detecting the pulses of the telegram a a trip lever actuated by said frequency selector in response to pulses received thereby, said trip lever, when actuated by the first pulse, of the telegram, closing a set of starting contacts for starting a motor;

a primaryv decoding cam having a track shaped in the image of the telegram driven by the motor so that its track rotates in synchronisation with the telegram r at least two secondary decoding cams coupled to each other and driven by the motor at a speed which is a multiple of the speed of the primary cam, each secondary cam having two tripping portions spaced apart by an angle corresponding to the time separating two order pulses after the interval of time reserved for the first pulse;

first and second feeler levers controlled by said tripping portions for executing, by means of respective bossed cams, close and open orders corresponding respectively to order pulses decoded by the frequency selector;

a common catch for locking said feeler levers in the absence of pulses and for unlocking them in the presence of order pulses, whereby when one of said tripping portions of a secondary decoding cam presents itself to its corresponding feeler lever in synchronisation with an order pulse, that feeler lever is actuated by said tripping portion and actuates in turn its corresponding bossed cam so as to make that bossed cam actuate its contacts.

2. A receiving relay according to claim 1, in which the shaped track of the primary cam has a first row of breakable crenelles for forming recesses corresponding to the starting and order pulses of the telegram to be decoded; and in which a principal peg is provided rigid with the trip lever for engaging in a starting recess and at the interior of a hollow profile provided on said primary cam, during the first pulse; said peg disengaging itself when an order recess presents itself such that between said recesses the trip lever maintains said motor starting contacts closed.

3. A receiving relay according to claim 2 adapted to decode two sorts of telegrams distinguished from each other in that one sort has a short first pulse and the other sort has a long first pulse, in which the trip lever is equipped with a supplementary peg blocked by the rotation of a hollow profile of the starting contact controlling cam when the first pulse is short, such that said lever mechanically blocks the frequency selector which becomes insensitive to order pulses transmitted after a first short pulse and for the entire duration of the telegram.

4. A receiving relay according to claim 2, in which the primary cam has a second track shaped in the image of the telegram, this second shaped track being in the form of a second row of breakable crenelles for forming recesses corresponding to the starting and order pulses of the telegram to be decoded; electrical contacts being provided which are opened at the passage of the recesses to unshort-circuit a winding of the frequency selector and these same contacts being closed outside the recesses in order to short-circuit said winding.

5. A receiving relay according to claim 2, in which axial teeth are provided on adjacent lateral faces of a feeler lever and its corresponding bossed cam, and in which the feeler lever executes an order by two successive movements, the first is a rocking of the end of said lever into the recess of the secondary rotating cam, for putting the axial teeth on the lever into engagement with the axial teeth on the bossed cam, and the second movement is a reverse rocking consecutive to the return of said end onto the exterior profile of the secondary rotating cam, for advancing said teeth such that the bossed cam rotates through an angle corresponding to the closing or the opening of the associated electrical contacts.

6. Receiving relay according to claim 5, in which the bossed cam comprises two axial sets of ratchet teeth disposed symmetrically on the two faces of said bossed cam, the feeler levers have a set of axial ratchet teeth bearing elastically against the corresponding set of teeth of the bossed cam, the teeth of one feeler lever being shifted by halfof said angle corresponding to the time separation between two order pulses, with respect to the teeth of the other feeler lever, such that the teeth of a feeler lever which has executed an open order are in direct engagement at the end of the rotation with the corresponding teeth of the bossed cam whereas the teeth of the other feeler lever are shifted by half a tooth forward with respect to the other teeth of the bossed cam while waiting for the execution of a close order such that furthennore said teeth in engagement at the end of the rotation cannot repeat a previously executed order.

7. Receiving relay according to claim 2, in which the secondary cams are coupled with their respective recesses in phase two by two such that one revolution of each secondary cam executes one order chosen out of two possible successive orders. I

8. Receiving relay according to claim 2, in which the secondary cams are coupled with a shift between their respective recesses such that one revolution of each secondary cam executes one order chosen among four possible successive orders. 

1. A receiving relay of the type used in centralised remote control systems for receiving in synchronisation a telegram of orders sent by a single emitter, without any pilot wires, over an electrical energy mains distribution networK, the telegram being formed by pulses produced by modulating a carrier and superimposed on the mains network, said receiving relay comprising: a vibrating reed frequency selector tuned to the frequency of the carrier for detecting the pulses of the telegram ; a trip lever actuated by said frequency selector in response to pulses received thereby, said trip lever, when actuated by the first pulse, of the telegram, closing a set of starting contacts for starting a motor; a primary decoding cam having a track shaped in the image of the telegram driven by the motor so that its track rotates in synchronisation with the telegram ; at least two secondary decoding cams coupled to each other and driven by the motor at a speed which is a multiple of the speed of the primary cam, each secondary cam having two tripping portions spaced apart by an angle corresponding to the time separating two order pulses after the interval of time reserved for the first pulse; first and second feeler levers controlled by said tripping portions for executing, by means of respective bossed cams, ''''close'''' and ''''open'''' orders corresponding respectively to order pulses decoded by the frequency selector; a common catch for locking said feeler levers in the absence of pulses and for unlocking them in the presence of order pulses, whereby when one of said tripping portions of a secondary decoding cam presents itself to its corresponding feeler lever in synchronisation with an order pulse, that feeler lever is actuated by said tripping portion and actuates in turn its corresponding bossed cam so as to make that bossed cam actuate its contacts.
 2. A receiving relay according to claim 1, in which the shaped track of the primary cam has a first row of breakable crenelles for forming recesses corresponding to the starting and order pulses of the telegram to be decoded; and in which a principal peg is provided rigid with the trip lever for engaging in a starting recess and at the interior of a hollow profile provided on said primary cam, during the first pulse; said peg disengaging itself when an order recess presents itself such that between said recesses the trip lever maintains said motor starting contacts closed.
 3. A receiving relay according to claim 2 adapted to decode two sorts of telegrams distinguished from each other in that one sort has a short first pulse and the other sort has a long first pulse, in which the trip lever is equipped with a supplementary peg blocked by the rotation of a hollow profile of the starting contact controlling cam when the first pulse is short, such that said lever mechanically blocks the frequency selector which becomes insensitive to order pulses transmitted after a first short pulse and for the entire duration of the telegram.
 4. A receiving relay according to claim 2, in which the primary cam has a second track shaped in the image of the telegram, this second shaped track being in the form of a second row of breakable crenelles for forming recesses corresponding to the starting and order pulses of the telegram to be decoded; electrical contacts being provided which are opened at the passage of the recesses to unshort-circuit a winding of the frequency selector and these same contacts being closed outside the recesses in order to short-circuit said winding.
 5. A receiving relay according to claim 2, in which axial teeth are provided on adjacent lateral faces of a feeler lever and its corresponding bossed cam, and in which the feeler lever executes an order by two successive movements, the first is a rocking of the end of said lever into the recess of the secondary rotating cam, for putting the axial teeth on the lever into engagement with the axial teeth on the bossed cam, and the second movement is a reverse rocking consecutive to the return of said end onto the exterior profile of the secondary rotating cam, for advancing said teeth such that the bossed cam rotates through an angle corresponding to the closing or the opening of the associated electrical contacts.
 6. Receiving relay according to claim 5, in which the bossed cam comprises two axial sets of ratchet teeth disposed symmetrically on the two faces of said bossed cam, the feeler levers have a set of axial ratchet teeth bearing elastically against the corresponding set of teeth of the bossed cam, the teeth of one feeler lever being shifted by half of said angle corresponding to the time separation between two order pulses, with respect to the teeth of the other feeler lever, such that the teeth of a feeler lever which has executed an ''''open'''' order are in direct engagement at the end of the rotation with the corresponding teeth of the bossed cam whereas the teeth of the other feeler lever are shifted by half a tooth forward with respect to the other teeth of the bossed cam while waiting for the execution of a ''''close'''' order such that furthermore said teeth in engagement at the end of the rotation cannot repeat a previously executed order.
 7. Receiving relay according to claim 2, in which the secondary cams are coupled with their respective recesses in phase two by two such that one revolution of each secondary cam executes one order chosen out of two possible successive orders.
 8. Receiving relay according to claim 2, in which the secondary cams are coupled with a shift between their respective recesses such that one revolution of each secondary cam executes one order chosen among four possible successive orders. 